New Test Identifies Positive Tuberculosis Cases Within the Hour

A new test can identify positive tuberculosis (TB) cases within one hour, ensuring quick treatment for patients and reducing the incidence and consequences of TB worldwide.

Researchers at the Health Protection Agency (HPA; London, United Kingdom) developed a new ultra rapid test for the TB bacteria, Mycobacterium tuberculosis, which substantially increases the sensitivity of the test, enabling detection of the presence of the bacteria in a sample within an hour. The new technique is a single DNA molecule identification test, which uses real-time polymerase chain reaction (PCR).

The new test focuses on a particular DNA region within the TB bacterium, which the researchers say is present in all strains of the disease. According to the researchers, the test can pick up very small amount of bacteria, and appears to be as sensitive as the gold standard TB identification, a bacterial culture grown from mucus coughed up from the lungs. However, the standard test can take up to eight weeks to reach a diagnosis, by which time the individual might have infected many more people. The study findings were presented at the HPA's annual conference, held during September 2010 at the University of Warwick (United Kingdom).

"We're excited to have developed this new test because it means we can potentially diagnose someone at a TB clinic within an hour and start them immediately on the treatment they need,” said study author Catherine Arnold, Ph.D., head of the HPA's genomic services unit. "This new test could really have an impact where it is most needed.”

TB is a common and often deadly infectious disease that usually attacks the lungs, but can also affect other parts of the body. Most infections in humans result in an asymptomatic, latent infection, but about one in ten latent infections eventually progresses to active disease which, if left untreated, kills more than 50% of its victims. The World Health Organization (WHO, Geneva, Switzerland) has estimated that one third of the world's population carries TB bacteria, and recent years have seen resurgence in TB infections in developed countries, as well as the rise of strains resistant to medication.

Related Links:
Health Protection Agency
University of Warwick
World Health Organization